I bought a Speedway Disc brake kit 910-31909 to replace my F1 brakes [maybe]. Rotors are heavier than I thought they would be. So thought of drilling faces and [like in early Mustangs] hubs to reduce weight [yah I think too much], holes help to braking by how much and why? Box the pads are in labeled "soft organic street". I thought I read semi-metallic in kit description [somewhere] and thats what they look/feel like. Big difference? Not concerned about wear. Going to call tomorrow.
Is this a drag car or street car? I'd seriously reconsider drilling a rotor. How much weight can you possibly be saving with a few holes in the surface of the rotor anyway? I'd venture a guess you wouldn't be able to tell once behind the wheel. Not to mention the possible weakening of the rotor itself. Now add in all the asshats driving while gawking at their cell phone and I'd think you would want as much braking material as possible! Just my 2 cents worth.
Soft Organic Street are the best for normal driving. They will never wear discs or groove them. They are also quiet.
Wagner has some of the best "all around" pads I've ever used. And being in the front end business for over 40 yrs I've seen, used, sold a lot but always come back to them. They have the least amount of brake dust on the wheels, the best wear to rotor wear, and they work extremely well in the stopping department wet or dry, cold or hot. They used to be called Wagner thermo-quiets now they call them Wagner TQ pads. I doubt there is a better street over the counter pad available so if they have them in your application I'd use them and never look back ! ...
The concept of drilling rotors is to dissipate heat build up under extreme braking (or at least used to be). road course racing and Fi racing was the thing that pushed that issue. On the street, if the rotors you have are vented, most of that problem has already been solved. The question then becomes, how often are you intending on doing road course racing at the level you believe more heat dissipation is going to be needed? The next purpose was weight reduction, again, unless you are doing serious street road course racing, is a couple pounds (pretty questionable) of weight reduction going to make the difference? Braking would not be the place I would start a weight reduction process, even if it was helpful.
I changed bolt pattern from Ford to chevy on a pair of rotors on my Henry J and never had any issues, not sure about drilling a bunch of speed holes in them though.
I think the purpose of drilling the rotors is to limit brake fade. Prevents gasses from building up between the pad and the rotor.
57 fargo is correct. Same reason for putting shallow slots in them. Drilling solids is probably ok(chamfer holes), but vented might be an issue. Also consider the rotor material strength. I've seen some of the castiron hats drilled out w/very large holes. Yes, I realize that weight reduction further out is more beneficial, but gets done where it can, I guess. Also very impressive, but I couldn't find or figure out the engineering/strength result(s). Wish that'd been available. ;( . Marcus...
Don't waste your time !! 99.99% of the factories don't, why would you ? The few "grams" that you'll be removing... Plus, I guarantee you...you'll screw up the balance...think about that ! Mike
Are these a hub/rotor unit, or separate hub and rotor? I find it hard to believe a separate rotor is “heavy”. Edit: I looked at the kit, it’s an integrated hub and rotor. Ie not a separate hub and rotor. I’d expect it to feel “heavier” if you are used to just swapping a rotor only.
Hello, There is a lot of good suggestions from all HAMB folks. Each one has their ups and downs, down being the most posted suggestions. As noted in a post, most early discs we saw in the late 60s early 70s were modified units from various sources. They looked cool and stopped better than drum brakes without all of the problems of heavy drums, water incursion and stopping power. Remember the suggestion of applying brakes, while driving through water of any kind? Water, brake pads, and steel did not always grab well when wet. The early discs had their own difficulties of similar consequences. Heat on solid metal did not always stop quickly and despite the pads, still had to keep some pressure in water of sorts. Jnaki Now, as the technology has raised the level to today’s standards, we now have vented discs that take the scientific action of throwing out water or any moisture/grime and what ever is down there out. Even keeping the disc solid to have as much surface area to grab. Weight? No problem and we do not have to drill holes in the plate to weaken them or allow “stuff” to get in and enjoy the ride. Ha! Old habits die hard as far as holes for light weight. We all know those extremes in holes for front axles and how cool they look. But the weakening effect is in full force and not the safest way to drive around. There is no substantial weight gain or loss to justify holes in discs. If you are set on buying them, that is your choice. But, holes are not necessary. YRMV
Ok no holes!! I couldn't remember that the holes were also for gas expelling. No road racing so all in all I guess I have no need for holes. My thought to replace the F1 brakes with disc is for less peddle effort in quick emergency stops. As an example I put Kelsy-Hayes 4 piston [early Mustang] on a OT car and effort was cut about in half, with no power assist. Would like to accomplish that again, or maybe just get more aggressive shoes. I checked the pads [919-3382] and they must be semi-metalic as a magnet sticks to them [?] even though the box says Soft Street Organic. I have no problem with using the above posted Wagner TQ if they would have lower pedal effort than the semi-metalic. I am not hard on brakes, its the emergency stops I worry about.
The holes are for "green fade" [gas building up between the pads and rotors] curved slots are better. This is why you are better off with stock organic pads [and change them more often] And they are less prone to "glazing" When I do hill-climbs or "bent-sprints" in my race car , I swap the pads from "Carbon Metallics" to stockers because they are better when cold My 83 compound pads took 3-4 laps to get up to play [imagine these pads on the 1/4 mile] Brakes are not an area for "monkey see, monkey do" ,and beware of some salesman helping you to re-invent the wheel with shit they're selling. My best advice without going through a shitload of calculations is to find a donor vehicle of similar weight and wheelbase AND vulture the whole braking system. The manufacturers got them well sorted for general usage
I bought a donor car for $250 and its chassis upgraded the transmission, steering, brakes, emergency brake and more on a custom car I had and won't mention and would have had to reengineer.
Forgot to mention. Had an OT BMW, that the PO had put aftermarket drilled(small holes) rotors(Dinan). As soon as they rusted - (Minn dd, remember), the pads wouldn't keep the rust from building up, so the pads got grooved. & braking availability got cut in half before I chucked the whole lousy mess. Drilled &/or slotted for track stuff, maybe, but I'll never do them for the street. Drilled hubs, now that's kinda interesting. Esp for a handbuilt or fun-runner. Marcus...
Kit has 71-79 big gm Calipers with 2.810 pistons and Ford F150 11.750" dia. drum/rotor, either application out weighs my car by at least 700 lbs. Got to be ok in the ability to brake. I have no problem with using the above posted Organic Wagner TQ if they would have lower pedal effort than the semi-metalic. I am not hard on brakes, no city during rush hr. Today there was a head on crash in front of me. I stopped when I saw stuff flying around leaving enough room for Fire and MT, hit the 4 ways and directed traffic coming from the west. Its the emergency stops I worry about.
I run Wagner TQ on everything I own and have owned since they came out +20 yrs? Like I stated in my other post, used a lot of others at the shop but always went back to those, never a customer complaint of any kind. What I don't like about most disc brake conversion kits is they usually use cheap pads, wildwood is about the only exception. But the cheap pads almost always came back to the shop once we installed their kits complaining of lots of brake dust, soft pedals and heat brake fade. After the first couple times we would inform the customer that they might experience this when they brought in their cars and kits to be installed. If we warned them first then they knew what to expect and the fact it was the pads and not an installation error. In normal driving most got 70,000 miles or more out of a set of TQ pads. Like I said they are a high quality product that lives up to their description and price tag... ...
Id pass. I bet if you compared the weight of the stock drums and hubs they'd weigh more than the rotors
Whole disc kit [nuts, bolts, brackets, hoses, rotor/hubs, calipers, pads] weighs 109#, minus few #'s for cardboard boxes. Loaded F2 backing plates are 30#, so the rest of F1, hubs, bearings, drums would have to weigh more than 70#'s.
I gave a mediocre try at looking up Wagner TQ [Thermo-Quiet] pads for 71 Impala, listing says they are Ceramic? I hadn't expected that, thought they would be some type of organic.
How many holes would it take, to get these down to an acceptable weight ? If you really want something lighter, they are available, but not cheap.
"Heavy rotors" usually means that they can be resurfaced a number of times. Lighter weight, not so much. I wish I had a nickel for every time a brake tech has told me that my rotors that had never been resurfaced are "under spec" so he needed to sell me new ones.
One time, this kid was telling me my rotors were too thin to resurface again. He showed me the size on his micrometer, quoted the spec which was cast into the rotor hat. So I checked to make sure it was zeroed correctly. It was, so I agreed to new rotors. The new imported rotors are much softer, and wear about 1:1 with Ceramic pads. Many shops don't even turn rotors any more.
LOSTONE : In a better search [rock auto] I find that for a 71' Impala Wagner TQ [ThermoQuiet] the TQ can be had in Ceramic or Semi-metallic. According to RA chart the semi-metallic has the best stopping power. What is supplied in brake kit is supposed to be semi-metallic but for peace of mind I have no problem with getting a set of Wagner pads, just want to make sure I should get the semi-metallic.
Usually ceramic costs a little more. They usually last a little longer and handle heat better. The original thermo quiets were semi metallic then technology has moved along and now the top end TQ are ceramic. On a daily driver the semi metallic are fine, if you were road racing I'd go ceramic or you want a pad that lasts longer. Semi metallic will handle your car just fine. ....
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